1. Field of Invention
This invention relates to compositions for plastics and, in particular, to compositions which enhance the physical properties of plastics.
2. Brief Statement of the Prior Art
The characteristic of plastics to acquire and hold a static charge creates problems in handling and use of molded and extruded products, particularly when these products are sheets or films. Some attempts have been made to obviate these problems by forming sheets and films with corrugated surfaces or by coating plastic surfaces with certain anti-static compounds which dissipate electrical static charges. Certain hydroxyalkyl fatty amines are among many compounds which have been tried as anti-static coatings for plastic products.
The coating of plastics requires an additional treatment during fabrication of products and the coatings only provide a temporary solution to the problem since they are ultimately worn from the surface during the life of the product. Improvements in the anti-static treatment or modification of plastics is, therefore, desired.
Small capacity, high pressure injection and metering pumps have been developed for incorporating liquid suspensions of pigments in plastics during injection and blow molding, extruding and pelletizing. While this approach avoids the hazardous dusts, inhalation toxicity, contamination and cleanup problems which are encountered with dry pigments, difficulty has been experienced in providing a liquid suspension of pigments that has a stable and sufficient viscosity for use with these pumps.